John A wrote:
unfortunately, the voltage is a bit too high- it puts out ~520VDC
(after a 3-pole filter 10uF/10H/10uF with 40kOhm bleeder
resistor). I am looking for some ways to bring this down to the
voltage I need.


As a first, simple, experiment disconnect the 10uF nearest the rectifier and
reconnect it in parallel with the other 10uF. Then see what DC voltages you
get when drawing currents between 120 and 230mA. If it is near enough to the
370v you require, then add suitable resistors to deliver the other supply
voltages and currents you've specified and you've got what you need.
=====================================
Suggest you have a look in the ARRL magazine QEX ,July/August 1999 ,
pages 51 through 55.
"A regulated 2400V Power Supply" , by VE6AXW

In this supply unit the output voltage is controlled by silicon
controlled rectifiers (SRCs) in the primary (120 or 230 V) winding

The principle of this scheme can be readily used for your 370V-DC power
supply .
The output voltage can be set to any voltage lower than the one provided
by the rectifier(bridge) in the secondary winding at the full supply
voltage to the primary winding.

For the other 2 lower voltages you need you can use a zener diode
/resistor arrangement with or without a high voltage ( use low cost 1500
V type)transistor if you really need a constant voltage at varying load.
Otherwise the lower voltages can be obtained from resistors, as per a
previous message in this thread.

The transformer must of course be able to supply the total current you need.
If you don't know the max current which can be drawn from the
transformer , you first measure the no-load output voltage and
subsequently load the secondary winding with suitable resistors until
the voltage has dropped by 5% The relevant current can then be taken as
the maximum for the transformer (practical approach)
The max current check can of course also be done with the
rectifier(bridge) connected (DC measurement)

Frank GM0CSZ / KN6WH